Calintz is the adopted son of King Helios and a famous hero known as "The Phantom of Avalanche" due to his victorious battles against monsters. He returns to the land of Shudelmir only to find out things aren't what they seem. The new emperor has made some unpopular decisions, and now a faction known as Vermillion opposes his rule. The fallen princess Juclecia attempts to regain her throne as well. Despite tragic memories from his past, Calintz decides to stay in the city, and accepts the position as the leader of the 7th Squad of Shudelmir military. There unravels a tale of mystery, love, political intrigue, and betrayal.

Magna Carta: The Phantom of Avalanche is a Korean-made role-playing game with Japanese-style gameplay mechanics and aesthetics. Enemies attack randomly, and battles are turn-based. Characters can move across a confined battlefield during combat. Movement, spells, and attacks cost turn points, which the characters are given each turn. Characters can execute ability attacks which deplete their TP bar, as well as perform powerful combos that require the player to press keys in certain rhythmical patterns.

Carta points are awarded for defeating foes. Carta are energy patterns that roughly correspond to elemental magic and are represented by Chinese characters, The player can distribute carta points freely to many characters attributes which affect their spells, range, attack and defense. The system is somewhat similar to the junctioning of Guardian Forces in Final Fantasy VIII.